Academic journal article Phi Delta Kappan

Later Start Time for Teens Improves Grades, Mood, and Safety: New Research Shows That High School Students Benefit in Many Ways from Later Start Times

Academic journal article Phi Delta Kappan

Later Start Time for Teens Improves Grades, Mood, and Safety: New Research Shows That High School Students Benefit in Many Ways from Later Start Times

Article excerpt

It all began with a phone call 20 years ago to the Center for Applied Research and Educational Improvement (CAREI) at the University of Minnesota in August 1996. The superintendent of Minnesota's Edina School District was reaching out to CAREI, seeking to discover if the new change in the start time of their high school--from 7:20 a.m. to 8:30 a.m.--would have any effect. I took that call. When I learned the reason for the change--namely, that the district's later start time purported to address developmental changes in the teenage brain related to sleep--I was skeptical. As a former teacher, school principal, and district office administrator in special education, I thought I had heard it all when it came to explaining teenage behavior. This association between brain development and teenagers was new to me.

But as we started our yearlong study, the evidence began piling up. Our research team found amazing changes were happening. Students were now awake the first hour of class, the principal reported fewer disciplinary incidents in the halls and lunchroom, and students reported less depression and feelings of greater efficacy. Over 92% of the parents said their kids were "easier to live with."

As the early findings from Edina were being reported, the Minneapolis Public Schools superintendent and school board decided a year later, in 1997, that they, too, would change the start times of their seven comprehensive high schools from 7:20 a.m. to 8:40 a.m. This change affected 52,000 K-12 students. The multitiered busing schedule moved elementary students to the earliest times, with high school and middle school students shifting to the later times. The outcomes for the Minneapolis students were similar to those for Edina, although the settings--urban as opposed to suburban--couldn't have been more different.

The medical research behind the change

What we know about human development and, most recently, about the maturation of the teenage brain lends credence to the fact that "it's a matter of biology, not choice" that teenagers are unable to fall asleep before about 10:45 p.m. and that their brains remain in sleep mode until about 8 a.m. This delay in the circadian rhythms for teenagers is directly related to hormonal changes during puberty. Most teens experience this so-called sleep phase shift only during adolescence; the shift will disappear as teens enter their 20s.

Teens need about 9.25 hours of sleep each night, a difficult amount to obtain when the brain doesn't enter sleep mode until about 10:45 p.m. and when students must awaken early for a school day that begins before 8:30 a.m. Medical research has shown dramatic negative effects of sleep deprivation, especially in people who are chronically sleep-deprived. Depression, obesity, substance use and abuse, and increased car crashes are just some of the serious consequences. From the early 1990s to now, the medical research findings about the sleep needs of teens became a significant body of knowledge (Carskadon, Acebo, & Jenni, 2004; Jenni, Achermann, & Carskadon, 2005).

From a slow start to a movement

High schools across the United States began grappling with the possibility of changing start times one school and district at a time. In the early 2000s, few schools had made the shift. Those that did were not inclined to be studied. Many believed that a public examination of the change would be fraught with politics, and they feared the change would be found to have no benefits (Wahlstrom, 1999).

Nevertheless, from 2000 to 2010, more than 400 superintendents and principals contacted me for information and guidance. They had questions about a later start time's effect on grades and sports and on how to solve transportation issues. This was a time of cautious inquiry, with school leaders wondering how their school boards or community would react. Administrators needed factual information from both the medical and education research worlds about brain development and how the two sources of information intersect. …

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